There are many ways to Rome they say, but stick to the smudest my Mom always told me I have got many questions on external sharing in Office 365, and this is a blog post on that using the new Modern Team Site template.
Start from the SharePoint app and click “Create Site”, select Team Site, and fill in site name:
Then add internal group members:
After Site is created click the cog-wheel and select site permissions:
From site permission select Share Site Only:
And share using the external users email address:
Possible permission levels are: Edit, read, and full control.
The external user receives an email:
After log-in he/she can collaborate, upload/edit on files and use comments just like your internal users:
Note: External sharing must be enabled on the Office 365 tenant level by the SharePoint admin (or Global Admin).
There are many advantages for using a Modern Team site, it’s modern so it supports the SPfx (SharePoint Framework) you can easily upgrade it with Microsoft Team support, it’s responsive and fast loaded, and supports the upcoming Hub Sites.
Happy Sharing!